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A 0.1-to-1.2GHz tunable 6th-order N-path channel-select filter with 0.6dB passband ripple and +7dBm blocker tolerance

A 0.1-to-1.2GHz tunable 6th-order N-path channel-select filter with 0.6dB passband ripple and +7dBm blocker tolerance

Authors :
R. van der Zee
Milad Darvishi
Bram Nauta
Source :
ISSCC, IEEE International Solid-State Circuits Conference Digest of Technical Papers, ISSCC 2013, 172-173, STARTPAGE=172;ENDPAGE=173;TITLE=IEEE International Solid-State Circuits Conference Digest of Technical Papers, ISSCC 2013
Publication Year :
2013

Abstract

Radio receivers should be robust to large out-of-band blockers with small degradation in their sensitivity. N-path mixers can be used as mixer-first receivers [1] with good linearity and RF filtering [2]. However, 1/f noise calls for large active device sizes for IF circuits and high power consumption. The 1/f noise issue can be relaxed by having RF gain. However, to avoid desensitization by large out-of-band blockers, a bandpass filter (BPF) with sharp cut-off frequency is required in front of the RF amplifiers. gm-C BPFs suffer from tight tradeoffs among DR, power consumption, Q and fc. Also, on-chip Q-enhanced LC BPFs [3] are not suitable due to low DR, large area and non-tunability. Therefore, bulky and non-tunable SAW filters are used. N-path BPFs offer high Q while their center frequency is tuned by the clock frequency [2]. Compared to gm-C filters, this technique decouples the required Q from the DR. The 4-path filter in [4] has only 2nd-order filtering and limited rejection. The order and rejection of N-path BPFs can be increased by cascading [5], but this renders a “round‿ passband shape. The 4th-order 4-path BPF in [6] has a “flat‿ passband shape and high rejection but a high NF. This work solves the noise issue of [6] while achieving the same out-of-band linearity and adding 25dB of voltage gain to relax the noise requirement of the subsequent stages.

Details

Language :
English
Database :
OpenAIRE
Journal :
ISSCC, IEEE International Solid-State Circuits Conference Digest of Technical Papers, ISSCC 2013, 172-173, STARTPAGE=172;ENDPAGE=173;TITLE=IEEE International Solid-State Circuits Conference Digest of Technical Papers, ISSCC 2013
Accession number :
edsair.doi.dedup.....9521713276ea6e5d845b7fa330962098
Full Text :
https://doi.org/10.1109/isscc.2013.6487686